In the early 80’s Perris had one of the first Sky Vans. They always flew it without a door. Jumpers sat on the floor without seatbelts and no carpet on the floor. On takeoff you could hear the assholes slam shut for the packing area.

Sparky

What does "On takeoff you could hear the assholes slam shut for the packing area." mean? Confused how a plane without a door could be slammed shut in the packing area on takeoff????